"After last season, free agency wasn't even a thought," said James, who hails from Akron, 40 miles from Cleveland.

"But I have two boys and my wife, Savannah, is pregnant with a girl. I started thinking about what it would be like to raise my family in my home town.

"I looked at other teams, but I wasn't going to leave Miami for anywhere except Cleveland. The more time passed, the more it felt right. This is what makes me happy."

Highest-paid sports stars in 2013

Source: Forbes Rich List

Floyd Mayweather (boxing) - $105m (£61m)

Cristiano Ronaldo (football) - $80m (£47m)

LeBron James (basketball) - $72.3m (£42m)

Lionel Messi (football) - $64.7m (£38m)

Kobe Bryant (basketball) - $61.5m (£36m)

After joining the Cavaliers as the first draft pick in 2003, James rose to superstardom over the next seven years before he was tempted to Miami in 2010, where he formed a devastating partnership with Chris Bosh and Dwyane Wade.

His announcement on leaving for Miami was made during a staged ESPN television show called The Decision.

It led to a backlash from Cleveland fans who burned James jerseys in anger.

James, who would have earned $20m (£11.7m) next season, won NBA titles with Heat in 2012 and 2013. He also led Miami to the NBA Finals in 2011, when they lost to Dallas, and 2014, when they were heavily beaten by San Antonio.

Speaking of his time in Miami, James said: "The hardest thing to leave is what I built with those guys. I've talked to some of them and will talk to others. Nothing will ever change what we accomplished. We are brothers for life."

Saturday's front page of Cleveland paper The Plain Dealer

News of James' departure was announced over the loudspeaker at Cleveland airport and Cavaliers ticket phone lines crashed,
reported ESPN.

In 2010, Cavaliers owner Dan Gilbert wrote an open letter criticising James and describing his departure as a "shocking act of disloyalty" and a "shameful display of selfishness and betrayal".

But on Friday
he tweeted:
"My eight-year-old: 'Daddy, does this mean I can finally wear my LeBron jersey, again?' Yes it does, son. Yes it does!"

In Miami, a mural featuring
James was defaced
- according to South Florida news station WPLG Local 10.

Heat owner
Micky Arison tweeted:
"I am shocked and disappointed in today's news. However I will never forget what LeBron brought us for four years. Thanks for the memories."

The situation could yet get significantly worse for the Heat. Wade and Bosh both joined James in opting for free agency this summer and may now follow their former team-mate's lead by confirming moves away from Miami.

In addition to the Sports Illustrated interview, James posted a photo of himself in a Cavaliers uniform on
Instagram
with the phrase "I'm coming home".

He told Cleveland fans not to expect instant success, however.

"When I left Cleveland, I was on a mission,'' James said. "I was seeking championships, and we won two. But Miami already knew that feeling. Our city hasn't had that feeling in a long, long, long time.

"I'm not promising a championship. I know how hard that is to deliver," James said.

"We're not ready right now. No way. Of course, I want to win next year, but I'm realistic. It will be a long process, much longer than it was in 2010. My patience will get tested. I know that."

Cardboard cut-outs of LeBron James were binned after he left Cleveland in 2010

BBC links

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